Display driving circuit and operating method thereof

Patent metadata

Field	Value
Publication number	US-11217199-B2
Application number	US-202016930708-A
Country	US
Kind code	B2
Filing date	Jul 16, 2020
Priority date	Apr 28, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

Disclosed are a display driving circuit and a display apparatus including the same. A display driving circuit includes a first amplifier configured to drive a first data line of a display panel based on first pixel data and a second amplifier configured to drive a second data line of the display panel based on second pixel data, wherein, when a first data difference between the first pixel data and the second pixel data is greater than or equal to a data value indicating one grayscale and is less than or equal to a first threshold value, the second amplifier is turned off, and the first amplifier is configured to drive the first data line and the second data line based on the first pixel data and the second pixel data.

First claim

What is claimed is:

1. A display driving circuit comprising:
a first amplifier configured to drive a first data line of a display panel based on first pixel data; and
a second amplifier configured to drive a second data line of the display panel based on second pixel data,
wherein the second amplifier is disabled and the first amplifier is enabled such that the first amplifier is configured to drive the first data line and the second data line based on the first pixel data and the second pixel data, when a difference between the first pixel data and the second pixel data is less than or equal to a first threshold value,
wherein the first data line is connected to a first sub-pixel of a first pixel and the second data line is connected to a second sub-pixel of a second pixel,
wherein the first sub-pixel and the second sub-pixel have identical color, and
wherein the first pixel is adjacent to the second pixel.

2. The display driving circuit of claim 1 , wherein the first amplifier is configured to,
drive the first data line and the second data line based on the second pixel data during a first sub-period of a horizontal driving period, and
drive the first data line based on the first pixel data during a second sub-period of the horizontal driving period.

3. The display driving circuit of claim 2 , further comprising:
a first output pad connected to the first data line;
a second output pad connected to the second data line; and
a connection switch connected to the first output pad and the second output pad, the display driving circuit configured to generate a control signal to turn on the connection switch during the first sub-period, and turn off the connection switch during the second sub-period.

4. The display driving circuit of claim 2 , further comprising:
a first decoder configured to output a first gray voltage selected from among a plurality of gray voltages, based on the first pixel data;
a second decoder configured to output a second gray voltage selected from among the plurality of gray voltages, based on the second pixel data; and
an input switching circuit configured to,
supply the first amplifier with the second gray voltage during the first sub-period in response to a control signal, and
supply the first amplifier with the first gray voltage during the second sub-period in response to the control signal.

5. The display driving circuit of claim 2 , further comprising:
a first decoder configured to select one of a plurality of gray voltages as a first gray voltage based on received first input data, and to provide the first gray voltage to the first amplifier; and
a second decoder configured to select one of the plurality of gray voltages as a second gray voltage based on received second input data, and to provide the second gray voltage to the second amplifier.

6. The display driving circuit of claim 1 , further comprising:
a controller configured to,
compare the difference with the first threshold value to generate a comparison result, and
generate a second enable signal and a control signal based on the comparison result, the second enable signal selectively enabling the second amplifier, and the control signal controlling an output path of the first amplifier.

7. The display driving circuit of claim 6 , wherein the controller is configured to calculate a plurality of first threshold values for each grayscale based on a first threshold voltage and a gamma register value.

8. The display driving circuit of claim 7 , wherein the controller is further configured to,
store the plurality of first threshold values in a look-up table, and
determine whether the second amplifier amplifies a data value of the first pixel data or the second pixel data based on the first threshold value, the first threshold value being selected from among the plurality of first threshold values.

9. The display driving circuit of claim 1 , wherein
the first pixel data corresponds to a first pixel connected to a K th scan line and the first data line of the display panel, K being an integer greater than or equal to 2,
the second pixel data corresponds to a second pixel connected to the K th scan line and the second data line, and
when at least one of (i) a second data difference between the first pixel data and first previous pixel data, which corresponds to a third pixel connected to a (K-1) th scan line and the first data line, and (ii) a third data difference between the second pixel data and second previous pixel data, which corresponds to a fourth pixel connected to the (K-1) th scan line and the second data line, is greater than a second threshold value, then, during a K th horizontal driving period,
the first amplifier is configured to drive the first data line based on the first pixel data, and
the second amplifier is configured to drive the second data line based on the second pixel data.

10. The display driving circuit of claim 9 , wherein the display driving circuit is configured to,
when the difference is less than or equal to the first threshold value and the second data difference and the third data difference are less than or equal to the second threshold value,
disable the second amplifier, and
enable the first amplifier to drive the first data line and the second data line during a first period of a horizontal driving period, and to drive the first data line during a second period of the horizontal driving period; and

set a length of the first period such that the length of the first period decreases when the second threshold value decreases.

11. The display driving circuit of claim 9 , further comprising:
a controller configured to,
compare the difference with the first threshold value;
compare each of the second data difference and the third data difference individually with the second threshold value to generate comparison results; and
generate a second enable signal and a control signal based on the comparison results, the second enable signal selectively enabling the second amplifier, and the control signal controlling an output path of the first amplifier.

12. The display driving circuit of claim 1 , wherein the first sub-pixel and the second sub-pixel have identical position within the first pixel and the second pixel, respectively.

13. The display driving circuit of claim 1 , wherein the display panel comprises:
a plurality of organic light-emitting diode (OLED) pixels.

14. The display driving circuit of claim 1 , wherein the first amplifier is configured to drive the first and the second data line simultaneously.

15. The display driving circuit of claim 14 , wherein the first data line and the second data line are connected via a switch in response to a switch control signal based on the difference between the first pixel data and the second pixel data.

16. The display driving circuit of claim 15 , wherein the display driving circuit is configured to be operated in a normal mode and to be operated in a low-power mode if the difference between the first pixel data and the second pixel data is less than or equal to the first threshold value.

17. The display driving circuit of claim 16 , wherein further comprises a control logic configured to disconnect the second amplifier to the second data line the difference between the first pixel data and the second pixel data is less than or equal to the first threshold value.

18. A display driving circuit comprising:
a first amplifier configured to drive a first data line of a display panel based on first pixel data;
a second amplifier configu

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kong Ki-Ho
• Kwon Taek-Su
• Kim Jong-Hyun
• Kim Jee-Hwal
• Park Jun-Ho
• Yune Hong-Keun

Classifications

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G3/36

  using liquid crystals · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G3/3258

  with pixel circuitry controlling the voltage across the light-emitting element · CPC title

• G09G2310/0275

  Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current · CPC title